Parkinson’s disease is one of the fastest-growing brain disorders in the world. It affects millions of people and becomes more common as people get older.
The disease slowly damages the brain cells that produce dopamine, a chemical messenger that helps control movement.
As dopamine levels fall, people may develop shaking, stiff muscles, slow movements, balance problems, and difficulty walking.
Many people also experience tiredness, sleep problems, constipation, loss of smell, anxiety, depression, and changes in thinking. Although medicines and exercise can help control symptoms, there is still no cure.
Scientists have long believed that Parkinson’s disease develops because of a combination of genes and environmental factors.
While some people inherit genes that increase their risk, many researchers think that exposure to harmful chemicals may also play an important role.
A new study from researchers at the University of Rochester and other institutions has added more evidence to support this idea.
The study focused on trichloroethylene, usually called TCE. TCE is a man-made chemical that has been widely used for more than 100 years.
It was commonly used to clean metal parts in factories, remove grease from machinery, dry clean clothing, and even remove caffeine from coffee many years ago. Although its use has declined in many countries because of health concerns, TCE has not disappeared.
One of the biggest problems with TCE is that it can remain in the environment for many years. It can leak into soil, pollute underground water, and slowly evaporate into the air inside homes, offices, schools, and other buildings.
As a result, people may breathe it in, drink contaminated water, or come into contact with it without realizing they have been exposed.
Scientists first suspected a link between TCE and Parkinson’s disease about 50 years ago. Since then, laboratory studies and smaller human studies have continued to raise concerns. The new research strengthens that evidence.
The research team, led by Dr. Ray Dorsey, reviewed previous scientific studies and carefully examined seven people who developed Parkinson’s disease after being exposed to TCE.
Although the number of cases was small, the researchers combined these findings with earlier evidence from animal studies and human research. Together, the results suggest that people exposed to TCE may have about five times the risk of developing Parkinson’s disease compared with people who were not exposed.
This finding is especially concerning because TCE contamination is still found in many places around the world.
Old industrial sites, military bases, factories, and dry-cleaning businesses are common sources of pollution. In some areas, the chemical has spread through groundwater and soil, meaning people living nearby may be exposed for many years without knowing it.
Unlike some risk factors that cannot be changed, exposure to TCE can often be reduced. Cleaning up polluted land, improving workplace safety, monitoring drinking water, and reducing the use of harmful industrial chemicals could help lower future exposure.
Better public awareness may also encourage communities to test contaminated sites and support environmental cleanup projects.
Researchers stress that more large studies are still needed to fully understand how much TCE contributes to Parkinson’s disease and why some people develop the condition while others do not. However, many experts believe the existing evidence is already strong enough to justify stricter environmental protections.
As Parkinson’s disease continues to become more common worldwide, preventing avoidable causes is becoming increasingly important. Identifying harmful chemicals in the environment may help reduce the number of future cases and protect brain health for generations to come.
The study was led by Dr. Ray Dorsey and colleagues from the University of Rochester and was published in the Journal of Parkinson’s Disease.
The findings add to growing evidence that environmental pollution may play a much larger role in Parkinson’s disease than previously believed and highlight the importance of reducing exposure to toxic chemicals whenever possible.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
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